Wire guide for a cabling machine

ABSTRACT

In accordance with an illustrative embodiment of the present invention, a high speed tubular strander is adapted for making armored cable through the provision of roller guide assemblies that are fixed to the strander tube at stations where the core changes direction of longitudinal travel. Each guide assembly has rollers that engage the periphery of the core and function to impart thereto a component of lateral motion so as to drive the core in reverse rotation to that of the tube to eliminate undesirable twist in the finished cable.

0 limited States Patent 1191 1111 3,732,68 Barrier 1 May 15, 1973 [541WIRE GUIDE FOR A CABLING 2,476,180 7 1949 Charles .57 9

MACHINE 2,723,525 11/1955 Blaisdell 3,407,587 l0 1968 M't h ll [751Inventor: Miller Houston, 3,456,433 7/1969 1131:1121: ..57/58.34 x [73]Assignee: Schluinberger Technology Corporation New York Primary Examm erDonald E. Watkins Attorney-Emest R. Archambeau, Jr., et al. 22 F'] d: N10 197 1 1 57 ABSTRACT l [2 1 App] No 197,326 In accordance with anillustrative embodiment of the v present invention, a high speed tubularstrander is [52] US. Cl ..57/58.34, 57/5836 adapted for making armoredcable through the provi- [5]] lint. Cl. ..D07b 3/12 sion of roller guideassemblies that are fixed to the [58] Field of Search ..57/9, 34R,58.32, strander tube at stations where the core changes 57/5834,58.36, 106, 138, 161, 166, 58.3, direction of longitudinal travel. Eachguide assembly 59 has rollers that engage the periphery of the core andfunction to impart thereto a component of lateral mo- [5 6]References'Cited tion so as to drive the core in reverse rotation tothat of the tube to eliminate undesirable twist in the UNITED STATESPATENTS finished cable 2,162,131 6/1939 Somerville ..57/58.36 X 6Claims, 5 Drawing Figures 13 II 20 5 24 27 v29 21 5 v 15 WIRE GUIDE FORA CABLING MACHINE This invention relates generally to tubular stranders,and more particularly to a new and improved high speed tubular stranderhaving the capability for making armored electrical cable.

In the prior art, several basic types of machines have been used in themanufacture of armored cable, wire rope, and similar products where anumber of wires are twisted in helical lays about a cable core. Onefairly common device is the planetary strander where the bobbinscontaining the wires are actually rotated about the core. The bobbinsare mounted in cradles that are driven by gear, chain or cam in such amanner their axes remain spatially fixed during movement around thecore. Inasmuch as rotation of the bobbin can be controlled, this type ofdevice has been used almost exclusively for making armored cable wheretorsion control is very critical to eliminate any twist in the wirestrands or the core. Another machine is the rigid strander whichoperates basically the same as the planetary strander except that thecradles are rigidly mounted and are not permitted to rotate relative tothe cage assembly. This type of machine is used primarily in themanufacture of cable having large wire strands where torque control isnot essential.

Both the planetary and the rigid strander machines have the inherentdisadvantage that the bobbins and cradles represent large rotatingmasses which appreciably limit the speeds at which these machines canoperate. In actual practice, these machines might make 100 lays perminute, for example.

The tubular strander, on the other hand, is constructed in such a mannerthat the bobbins do not rotate about the core but are mounted in-line ingimballed cradle assemblies within a long cylindrical tube. The wirefrom each bobbin is brought to the outside and then longitudinally alongthe tube by wire guides to the front end of the tube where they passover a preforming head and then through a closing eye as they aretwisted over the core. Since the bobbins do not rotate about the core,the amount of rotating mass is appreciably reduced thereby enabling muchgreater rotational speeds. For example, the tubular strander might make1000 lays per minute compared to 100 lays for the planetary or the rigidstrander.

In the past, however, the tubular strander has been largely limited tosmaller cable or wire rope manufacture and has not been useful in makingarmored cable because of the difficulty in passing the relatively largearmor wires over the outside of the tube and returning. The wire torqueassociated with tubular stranders has also limited their application toproducts not requiring the stringent torque control that is desirable inarmored cable making operations.

The general object of this invention is to provide a new and improvedtubular strander capable of manufacturing armored cable at high speedoperation.

This and other objects are attained in accordance with the concepts ofthe present invention through incorporation in a tubular strander ofcurved guides having rollers in contact with the core at points wherethe core changes directions of axial travel. The rollers are mounted inpairs and are inclined at an acute angle with respect to the axis of thecable. Thus as the core moves axially, the rollers impart a lateralcomponent as well as an axial component of motion to the peripherythereof, with the overall effect being to drive the core in a rotationaldirection that is reverse to that of the tube to fully compromise anytwisting action that would otherwise occur. The ratio of circumferentialmovement to axial movement imparted by the rollers to the core, forexample, can be altered by adjusting the angle that the axis of eachroller makes with the core. However, in a preferred embodiment, thisangle is made equal to the arc tangent given by the circumference of thecore divided by the lay length or pitch of the wire being stranded.

The present invention has other objects and advantages which will becomemore clearly apparent in connection with the following detaileddescription of the structure and operation of a preferred embodimentthereof, taken in conjunction with the accompanying drawings in which:

FIG. 1 is a somewhat schematic view of a tubular strander thatincorporates the principles of the present invention;

FIG. 2 is a detailed isometric view of a wire guide and mounting block;and

FIGS. 3-5 are fragmentary views showing the angular disposition of therollers with respect to the wire or core.

Referring initially to FIG. 1, a high speed tubular strander is shownschematically as including an elongated tube or barrel 10 having atapered section 11 at its rearward end connected to a hollow shaft 12which is journaled for rotation in a bearing 13 that is mounted in avertical strand 14. The forward end of the tube 10 is journaled forrotation in a bearing 15 mounted in a stand 16, and also has a taperedend section 17. Suitable means (not shown) are provided for rotating thetube 10 at high rpm as described above. The core 18 about which the wirestrands are to be helically layed is fed in from a payoff spool 19through the shaft 12 and brought through an opening 20 to the outside ofthe tube 10. From here the core 18 extends along the outside of the tube10 through eyes, tubes or other typical guides to another opening 27where it comes back into the tube It) and is made to pass out throughthe center of tapered section 17. Thus the core 18 enters and exitsalong the axis of rotation of the tube 10, and upon exit passes througha closing head 22 where the armor wires are positioned thereon, and thefinished cable passes around a capstan assembly 23 to a take-up spool(not shown).

The tube 10 has a plurality of vertically disposed partitions 24 whichmount, in gimbal fashion, a series of cradle assemblies 25 in-line withthe rotation axis of the tube. The assemblies 25 are gravity biased byweights or the like to remain in substantially level altitude duringrotation of the tube 10. The cradle assemblies 25 each carry a bobbin 26containing a strand of armor wire 27, the wire being fed through ahollow cradle trunnion 28 and then through an opening 29 to the outsideof the tube 10. The wires 25 fed along the outside of the tube 10 to itsforward end where they pass through wire guides 30 and through apreforming head 31. After preforming the wires proceed into the closingeye 22 where they are positioned in helical lays over the core 15. Forpurposes of clarity the tube 10 is shown foreshortened in FIG. 1,however, it will be appreciated that in actual practice the tube isquite lengthy and contains a large number of bobbins containing thearmor wires used for armored cable making operations.

As previously mentioned, the primary advantage of this type of machinelies in its capability for high speed operation. However, difficultieshave been encountered in the past in connection with passing the wiresand the core over the outside of the tube due to the sharp turns thatwere necessary in coming to the outside and returning. Moreover, acertain amount of undesirable torque was applied to the wire due tofrictional engagement with the outside wire guides as the tube rotates.There was also an inherent tendency of the wires to cause the core to betwisted somewhat as they arelaid helically thereon at the closing head.These difficulties have heretofore largely limited this type of machineto the manufacture of smaller wire rope and cable, and to cable wherestringent torque control is unnecessary.

In accordance with the principles of this invention, a plurality of wiredrive guide assemblies 35 are mounted at the various stations on themachine where the core 18 changes direction of travel. Each wire driveguide assembly 35 serves two primary functions (1) to impart a reversetorque to the core to neutralize its tendency to be twisted in thedirection of rotation of the tube 10, thereby enabling precise torquecontrol, and (2) to provide a curved path of large radius for the coreto avoid yielding that would otherwise result from too sharp bends.

Referring now to FIG. 2, the structural details of a guide assembly 35will be explained in connection with its cooperative relationship to thecore 18 of the cable, and it will be appreciated that the same orsimilar principles apply with respect to the armor wires. That is tosay, the guide assemblies described below may be attached to the tube atpoints where the armor wires change direction of axial travel as shownschematically in FIG. 1. In any event, a mounting block 36 is adapted bysuitable means to be secured in fixed position on the tube 10 and has alongitudinally extending inclined recess 37 that is sized to receive aguide beam 38. The guide beam 38 has a smoothly curved outer surface 39into which are formed two series of spaced apart pockets 40 and 41located in alternating fashion, each pocket being adapted to receive aroller assembly 42. Each roller assembly 42 is constituted by a roller43 (FIG. 5) that is mounted on a shaft 44 having screw threads 45 forattaching the roller assembly within a respective pocket 40 or 41.

As shown in FIGS. 3-5, each roller 43 is mounted for rotation about anaxis that is inclined to the side of a line perpendicular to the outersurface of the guide beam 38, preferably at a 45 angle, in order toprovide a well defined path for the core 18 through the guide. Moreover,each roller 43 is inclined with respect to a plane that is perpendicularto the longitudinal axis of the core 18 by an acute angle 6. By virtueof the inclination of the roller 43 by the angle 0, it will be apparentthat as the core 18 causes the roller to rotate by engagement therewithas it runs past the roller, the roller through frictional contact willimpart a lateral component of motion to the periphery of the core. Bychoosing the correct value for the angle 6, the tendency of the core 18to be twisted due to frictional forces as it passes longitudinally alongthe outside guides on the strander tube 10, or as the wires 27 are laidthereon at the closing head 22 can be precisely neutralized by anopposing torque. It has been found that a correct value for the angle 0is the arc tangent given by the circumference of the core 18 divided bythe lay length (pitch) of the armor wire being stranded.

In operation, as the core passes over a wire drive guide assembly 35,each roller 43 provides a point of support so that the virtual turnradius is large to avoid sharp bends or turns that would otherwise causethe wire to yield in an undesirable manner. Each roller 43 also impartsa lateral component of motion to the periphery of the wire or core whicheffectively drives it in a reverse rotation to that of the tube 10 toeliminate undesirable torque that has been associated wit priorstranders. Since stringent torque control can be had through use of thepresent invention, it is now possible to manufacture armored cable atthe high speeds afforded by tubular stranders.

Since certain changes or modifications may be made by those skilled inthe art without departing from the inventive concepts of the presentinvention, it is the aim of the appended claims to cover all suchchanges and modifications falling within the true spirit and scope ofthe present invention.

I claim:

1. Apparatus for use in a high speed tubular strander adapted tomanufacture cable wherein armor wires are laid about a cable core thatpasses along a tortuous path through a rotating tube, comprising aroller guide assembly adapted to be fixed to said tube at a point wheresaid core changes directions of axial travel, said guide assembly havinga plurality of rollers adapted to engage the periphery of said core,each roller being mounted for rotation about an axis that is inclinedwith respect to the axis of said core so as to impart a lateralcomponent of motion to said periphery tending to drive said core in arotational direction opposite to that of said tube.

2. The apparatus of claim 1 wherein said rollers are mounted in pairs atspaced points along a guide beam having a curved outer surface.

3. The apparatus of claim 1 wherein the rotation axis of each roller isinclined with respect to the axis of said core by a principal anglewhose tangent is given by the circumference of the core divided by thelay length of wire being laid about said core.

4. Apparatus for use in a high speed tubular strander adapted tomanufacture cable wherein armor wires are laid about a cable core thatpasses along a tortuous path between the inside and the outside of arotating tube, comprising: a mounting block adapted to be fixed to saidtube at locations where said core changes directions of axial travel; anelongated guide beam fixed to said mounting block and having a curvedouter surface; and a plurality of pairs of roller guides attached tosaid guide beam at spaced points therealong, each roller guide beinginclined to the side of a line perpendicular to the surface of saidguide beam in a manner to provide a curved travel path of large radiusfor said core, each roller guide further being inclined with respect tothe longitudinal axis of said core so as to impart a lateral componentof motion to the periphery of said core tending to drive said core in arotational direction that is opposite to that of said tube to enablestringent control of torque during a cable making operation.

5. Apparatus according to claim 4 wherein each roller guide is inclinedwith respect to the axis of said core by a principal angle whose tangentis given by the circumference of the core divided by the lay length ofwire being laid about said core.

6. Apparatus according to claim 5 wherein each roller guide ispositioned partially within a pocket formed in the outer surface of saidguide beam.

1. Apparatus for use in a high speed tubular strander adapted tomanufacture cable wherein armor wires are laid about a cable core thatpasses along a tortuous path through a rotating tube, comprising aroller guide assembly adapted to be fixed to said tube at a point wheresaid core changes directions of axial travel, said guide assembly havinga plurality of rollers adapted to engage the periphery of said core,each roller being mounted for rotation about an axis that is inclinedwith respect to the axis of said core so as to impart a lateralcomponent of motion to said periphery tending to drive said core in arotational direction opposite to that of said tube.
 2. The apparatus ofclaim 1 wherein said rollers are mounted in pairs at spaced points alonga guide beam having a curved outer surface.
 3. The apparatus of claim 1wherein the rotation axis of each roller is inclined with respect to theaxis of said core by a principal angle whose tangent is given by thecircumference of the core divided by the lay length of wire being laidabout said core.
 4. Apparatus for use in a high speed tubular stranderadapted to manufacture cable wherein armor wires are laid about a cablecore that passes along a tortuous path between the inside and theoutside of a rotating tube, comprising: a mounting block adapted to befixed to said tube at locations where said core changes directions ofaxial travel; an elongated guide beam fixed to said mounting block andhaving a curved outer surface; and a plurality of pairs of roller guidesattached to said guide beam at spaced points therealong, each rollerguide being inclined to the side of a line perpendicular to the surfaceof said guide beam in a manner to provide a curved travel path of largeradius for said core, each roller guide further being inclined withrespect to the longitudinal axis of said core so as to impart a lateralcomponent of motion to the periphery of said core tending to drive saidcore in a rotational direction that is opposite to that of said tube toenable stringent control of torque during a cable making operation. 5.Apparatus according to claim 4 wherein each roller guide is inclinedwith respect to the axis of said core by a principal angle whose tangentis given by the circumference of the core divided by the lay length ofwire being laid about said core.
 6. Apparatus according to claim 5wherein each roller guide is positioned partially within a pocket formedin the outer surface of said guide beam.